Method of manufacture of bags



July 16, 1929.

KLEIN METHOD OF MANUFACTURE OF BAGS 3 Sheets-Sheet Filed Feb. 3, 1928 July 16, 1929'.

E. KLEIN METHOD OF MANUFACTURE OF BAGS Filed Feb. 3, 1928 3 Sheets-Sheet 2.

' July 16,1929. KL IN 1.721599 METHOD OF MANUFACTURE OF BAGS Filed Feb. 5, 1928 v 3 Sheets-Sheet 3 ram Patented .luly Iii, 1929.

UNITED STATES ERNST KLEIN, or LENGERIGH IN WESTFALEN, GERMANY.

METHOD OF MANUFACTUREOF BAGS.

Application filed February 3, 1928, Serial No. 251592, and in Germany October 24, 1925.

around a former. In this m an ner of manufacturing, the inner sheet must be drawn forward a little by hand at the side of the .bag where the contents are to be inserted so that itsedge projects beyond that of the outer sheet or sheets. The projecting edge must then be turned over to the outside and pasted in order to ensure that the upper edge is not damaged on inserting the contents or that the goods are not wrongly inserted.

This invention embodies an improved method of manufacturing paper bags. Ac-

cording to the invention, inner and outer 7 layers are. formed from a single sheet turned over on the insertion side toa folded edge,

and between these two layers there are inserted additional sheets in the case of'bags to he madepof more than two layers eitheras single sheets or as sheets also connected together by a folded edge, whereupon they may be. pasted. At one side, the fold is cut open to the width required for the Formation of the adhesive seam, and between the flaps formed by such cutting the oppositely located edge is pushed in by folding together into a tube.

This method is hereinafter explained with v reference to the partly diagramn'mtic drawings. which illustrate the manufacture of double and multiple bags, aswell as the for:

mation of specially strong bottoms and an insertion flap on one SidGr-Of the-bag.

Fig. 1 illustrates a folded strip for making the bag, the two layers of'which constitute the inner and outer sheet in the case ofa double walled bag and the inmost and. outmost layer in the case of a nmlti-walled bug. Fig. 2 illustrates the arrangement of the sheets for a bag of three layers and Fig. 3

I illustrates the arrangement of the sheets for a bag of four layers. prior to their being shaped. into a flat paper tube.

Figs. dand 5 respectively illustrate in two different constructions, the manner in which the sheets are folded and glued to form paper tubes for a bag with three layers for exam 1e, by using the arrangement of sheets accord ng to Fig.

Fig. 6 illustrates the manner of attaching the flap portions together in a longitudinal seam to form the tubes shown in Figs. 4 and 5.

Figs. 7 to 9 show various stages of forming the bottom for the bag to be made from the tube of Fig. 4. v

Figs. 10 to 12 show a different form of bottom construction for the bag to be made I from the tube of Fig. 5.

Figs. 13 and 14 show the manner of proyiding an insertion flap in the bottom of the tion and somewhat diagrammatic.

In making a double bag, the paper sheet used should be of a widthabout twice the length a of the ba tube. This paper sheet iscut up intolengt s 6 see Fi 1) of about double the width of the ag to be the width of a double seam. The sheet is folded along a fold-line 0 as re resented. in

other occupying position a, and the length :of'whieh is indicated by a.

The fold a is slit at one end as represented at '(Z for an extent 'corrospomling with. the

Fill the figures are in plan or sideelevae made, plus desired width of the seam of thebag to be pasted. so as to provide two flaps ll and d".

This doubled sheet of Fig. 1 may be formed on a machine by feeding a aper strip from a roll of the width 2"--r v. olding over at c with the helpof folding devices,. and cutting the same into lengths b, theshort slits d at the fold 0 being formed at. the same time. At

the place where the fold a isformed, paper may be slightly perforated.

The double sheet is now formed into a tube, either by pasting the inner surfaces or edges of the folded sheets between the two flaps d and d" or the opposite end e of the piece on both sides with adhesive, slipping the the end 6 between the two flaps d and d and pressing down the two flaps. In machine manufacture impressions may be applied by well known means such as folding knives along the dotted lines f, 9 before or during the cutting of the paper band into the lengths b.

In'the way hereinafter explained for the manufacture of triple bags, the folding over into a tube can take place in such manner that the longe yer a form either the inner or outer lay r of the ba In the manufa ture of a rec-fold bag, a third sheet h 0 the same width b is inserted in the doubled sheet of Fig. l, the lower edge h thereof being made to' lie approximately in the middle between the edges of the layers a and a so'that a stepped graduation of the edgesis presented as shown in Fig. 2. The upper edge hf, of'the sheet k may extend up to the folded edge 0 and there stuck down by a narrow adhesive strip, especially if a flap bag is to be made. In some cases the sheet may be shortened somewhat on the side of the fold 0 in the .way indicated by the double dotted line 71/.

The inserted sheet 72. may be drawn out at the side of the edge e for about half the extent of the slit d, which then takes up thedouble width of the pasting seam. The formation of the seam is then completed as above described for a double bag. This formation is illustrated even more clearly in Fig. 6. It will be seen that not only the edge e is stuck in between the two flapsd and df, but that also the edge of the sheet h parallel to e is stuck fast on both sides to'the flaps d, d". This triple "tube can also be formed from lengths b drawn ed a roll, out off and previously provided with impressions determining the later folding edges by machine. The sticking together in tube form may be done mechanically in the way already described-for the doubletube, either according to Fig. 4 so that the layer a lies outside whilst the inner layers It and'a project outwardly in step formation, or in such manner that the layer a lies inside as indicated in Fig.

5, so that the edgesrecede in step formation inside. the tube.

The manner of .forming a quadruple bag will be understood readily upon reference to Fig. 3. The only difference is that the inner insertion consists of a doubled sheet z'ar; ranged so that a similar step formation of edges is presented at the lower end ofthe sheets. The bag tube formed therefrom would exhibit the layers in step formation outwardly or inwardly as in the case of the triple layer tube of Figs. 4 and 5.

Two ways of making bottoms for and from bag tubes formed in the above, described manner are illustrated by way of example, using the triple bag tube of Figs. 4 and 5 as a model.

For making the bottom from the tube of Fig. 4, the lower end of the tube is first folded on the line ff and triangular folds or flaps are then formed by folding oppositely on the linesme producing a rectangular bottom fold as represented in Fig. 7. so that the edges of the layer a" projecting towards the longitudinal center plane of the bag will slightly and that the work of making the bottom including the gluing'down of the strips can be carried out also by machinery.

For making the bottom from the tube of Fig. 5. wherein the shortest layer a lies inside and the longer layer a outside, the following method is preferably adopted. Triangular foldsor flaps m are formed to the .folding line AB at both edges of the tube.

Then a'stout paper strip 'n of the shape illustrated in Fig. 11 is covered with paste and stuck over the flaps m as indicated by dot and dash lines in Fig. 10, wherein it is shown in' glued down position near the edges of the layers stepped inwardly. Thereafter, the turned over' portions are folded downwardly over the lines C D and E-F and glued to the strip n, one of said portions '(in this instance the one folded over the line EF) being coated with adhesive on its underside so that its edge 0 will be glued firmly to the bottom, (see'Fig. 12).

The upper end of Fig. 5 and Figs. 13 and 14 illustrate the formation of a filling in valve bottom suitable also for the tube of Fig.

4 or Figs. 7 to 9. In order to form this bottom, triangular flaps 7), p are formed to the folding line GH. Then a closure strip g of approximately twice the width of the formed tube is pushed under the flap p on one side as indicated by the double dot dash line in Fig. 13. The flap-shaped portions r, 1' are then turned over along the fold lines K-L and M-N and pasted down as represented in Fig. 14. The width of the strip 9 is-such that the two folding edges 0 of the flap portions 7', 1' meet without overlapping each other. Thereafter, the outward extending part of the closure strip 9 is folded down as indicated by the arrow in Fig. 14 and glued to place. Said strip reinforces the seam at the bottom and forms aprolonged filling tube as indicated at s in Fig. 14, so that a secure closure is ensured. When such a filling in valve bottom is to be made, it is expedient as above mentioned to insert the upper edge It of the intermediate layer up to the" fold c and to fasten it by a narrow adhesiive strip. In some instances, instead of the folded strip 9 there may be used two separate strips of half its length to be glued to each other;

Having now particularly described and ascertained the nature of my said invention and in what manner the same is'to be performed, I declare that what I claim is 1. The method of manufacturing bags from sheet material in two or more layers united along a longitudinal seam, characterized by folding or doubling one of the sheets to form the inmost and outmost layers and inserting other sheets there'between with the fold of said inmost and outmost layers located along the upper end, cutting said fold slightly at one side or corner to provide flaps along a longitudinal margin of the bag under formation, pasting the edges of the layers along the opposite margin between said flaps to form a tube, which may thereafter be flattened by folding on intermediate longitudinal lines, and forming a bottom by folding and uniting the bottom end-portions of the flattened tube, substantially as described.

2. The method of manufacturing paper bags according to the preceding claim, characterized by the fact that additonal layers of paper inserted between the folded inmost and outmost layers are of a length equal to the circumference of the tube and are displaced laterally from the incised fold by substantially one-half the width of the adhesive seam. Q

3. The method of manufacturing paper bags according to claim 1, characterized by the fact that the intermediate layers are cut, folded and inserted in such relation that they are of different lengths in step-like arrangement longitudinally of the tube under formation, such arrangement being made either inwardly or outwardly of the tube with the folded inmost and outmost layers providing the length extremes.

1. The method of manufacturing paper bags according to claim 1, characterized by the fact that the inserted sheets are brought nearly up to the fold of the outmost and inmost layers and are fastened down by a narrow adhesive strip of paper.

5. The method of manufacturing paper bags according to claim 1, characterized by thefact that the inserted sheets are shortened at the side of the fold uniting the outmost and inmost layer.

6. In the manufacture of paper bags according to claim 1, the method of forming a bottom for and from the paper tube formed with layers in step-like arrangement out wardly, which consists in forming triangufrom the opposed longitudinal;

lar flaps edges to points midway of the width of the tube, pasting a rectangular piece of paper across the flaps thus formed and made to overlap transversely of the tube bottom, and then folding of the bottom square of the tube over the longitudinaledges of the paper piece pasted thereacross, whereupon a rectangular clo- -cu're member may be pasted thereover.

sheet with one edge thereof and pasting the two corners.

7. The method of forming a bottom from a paper bag tube manufactured according to claim 1 with several layers in ste -like arrangement, characterized by the act that an insertion piece 'of stout paper is introduced into a satchel bottom formed in the usual way, to which piece the edges of the several stepped layersare stuck.

8. The method of forming a satchel bottom for a paper bag tube, of several thicknesses manufactured according to claim 1, characterized by the fact that two overlying flaps for the satchel bottom are made in the usual way and are pasted in between two layers of a double closure strip of suitable width, said strip being of a length equal to double the width of the bag and formed by with sides of more than two layers of sheet material, which consists in transversely folding one of the sheets, inserting therebetween the folded layers of another folded sheet of a width approximately equalling the circumference of the bag tube tobe formed with its longitudinal edges displaced laterally from the longitudinal edges of the folded sheet, forming the sheets so assembled into a flat tube and closing one end of the tube by folding and pasting together portions of the bottom thereof.

11. The method of manufacturing bags with sides of a plurality of layers of sheet material, which consists in transversely sheet of a length substantially double'the length of the bag to be formed so that one edge thereof opposite the fold will project beyond the adjacent parallel edge, insertlng another sheet between the folds of the first projecting to a of the point intermediate the parallel edges folding one folded sheet, slitting the folded sheet along its fold for a distance equal to the width of the longitudinal seam to be formed so as to provide flaps along one side, forming the sheets into a flat tube having its axis perpendicular to the fold, securing the free edges of the sheets opposite to'the flaps between the latter and closing the end of the tube opposite the fold.

12. The method of manufacturing bags with sides formed by a plurality of layers of sheet material, WhlCh consists in transversely folding a sheet; of a length substantially of the longitudinal seam to be formed, folding the composite sheets on longitudinal lines providing a flat tube haying its axis perpendicular to the fold, and securing the side edges of the sheet layers between flaps formed on' the opposite sides by the aforesaid slitting of the fold and then forming a bottom for and from the tube. w

13. The method of manufacturing bags with sides of a plurality of layers of sheet material, which consists in transversely folding one sheet of the material, slitting the fold thereof at one corner for a distance equal to the width of a predetermined longitudinal seam, folding the folded sheet into a flat tube having its axis perpendicular to the 'fold, shaping the end of the tube opposite the fold end, fastening the sheet layers between flaps formed by turning back the. longitudinal edges at the slitted side, pasting a pieceof ma terial over the turned edges of the tube so as to partly cover said flaps, and folding the uncovered parts of said flaps over said material and securing the same thereto by adhesive.

14. The method of manufacturing bags with sides of a plurality of layers of sheet material, which consists in transversely folding a .sheet of material, slitting the fold at one side for a distance equal to the width of a predetermined longitudinal seam, folding the doubled sheet "longitudinally into a fiat tube having its axis perpendicular to the transverse fold, shaping the end of the tube opposite the transverse fold, forming longitudinal flaps by oppositely turning the iongitudinal edges of the inner and outer layers at the slitted side of the sheet,cpasting a piece of materialover the turned edges of the tube sheet partly covering said flaps, folding the uncovered parts of the said flaps over said;

one side or corner for a distance equal to the Width of a predetermined longitudinal seam, folding the folded sheet longitudinally to form a flat tube having its axis perpendicular to the transverse fold, shaping the end of the tube opposite the transverse fold, forming longitudinal flaps by oppositely turning the longitudinal edges o f'the sheet layers atthe slitted side, pastinga piece of material overand partly covering said flaps so as to leave a portion of said material projecting beyond the same, folding the uncovered parts of said flaps over the adhering portion of material, and securing the projecting portions of the material oyer the folded parts of said flaps by means of adhesive.

16. The method of manufacturing paper bags according to claim 1, characterized by the fact that the outer and inner layer sheets are formed by cutting pieces from a paper strip folded together along an approximately central longitudinal line as it is drawn ofli' a roll, said strip being of a width equal to substantially double the desired length of tubes to be formed and the pieces being out there'- from to a width equal to the desired circumference of the tubes plus the desired width of adhesive seam.

17. The method of manufacturing paper bags according to claim 1, characterized by the fact that the outer and inner layer sheets are formed by cuttingpieces from a'paper strip folded together along an approximately central longitudinal line as it is drawn off a roll, said strip being of a. Width equal to substantially double the desired length of tubes to be formed and the pieces being cut therefrom to a width equal to the desired circumference of the tubes plus the desired width of adhesive seam and then stamped out lengthwise( along desired fold lines.

signature.

ERNST KLEIN. 

